The present invention relates to improvements in the operation and functioning of devices for measuring predetermined volumes of a liquid sample and possibly subjecting said volumes to analytical operations. Such devices are described in U.S. Letters Pat. Nos. 3,986,534 and 4,070,248, the disclosures of which are incorporated herein by reference.
It has been found that after molding and assembly of such devices, the fluid flow during measurement of such predetermined volumes of liquid sample is ofter uneven such that the subsequent analytical operations are incapable of being performed.
It has been further found that such fluid flow can be significantly and substantially improved by addition to the liquid sample to be measured of a small amount of polyvinylpyrollidone.